Automobiles with internal combustion engines to burn fuel such as gasoline, for example, employ a fuel vapor recovery system for collecting fuel vapors generated in fuel tanks. The recovery system includes a canister. The canister temporarily stores fuel vapors generated in a fuel tank. When an engine is started, the fuel vapors are drawn from the canister into the induction system of the engine.
The canister is generally preferably mounted near the fuel tank so as to shorten piping from the fuel tank to the canister. In view of arrangement space in the vehicle, it is especially preferable to arrange the fuel tank in a vehicle rear portion and arrange the canister behind the tank. A mounting structure for this kind of canister is disclosed, for example, in Japanese Patent No. 3241552.
The canister mounting structure disclosed in Japanese Patent No. 3,241,552 will be described below with reference to FIGS. 6 and 7.
Referring to FIGS. 6 and 7, a vehicle 100 includes, at the rear of a vehicle frame 101, longitudinally extending left and right rear side frames 102, 102, a crossmember 103 extended therebetween, and a subframe 104 arranged below the crossmember 103 and extended between the left and right rear side frames 102, 102. The subframe 104 supports rear suspensions, not shown.
A fuel tank 111 is arranged forward of the crossmember 103. A canister 112 is mounted to the undersurface of the crossmember 103. The canister 112 is disposed between the above-located crossmember 103 and the below-located subframe 104.
The canister 112 protrudes rearward from the crossmember 103 and the subframe 104. If an obstacle collides with the rear of the vehicle 100 (hereinafter referred to as “at a rear-end collision”), the vehicle rear 105 plastically deforms in a forward direction as shown by imaginary lines in FIG. 6, abutting on the canister 112.
The canister 112 has a simple configuration filled with an absorbent such as activated carbon for absorbing fuel vapors and is basically harmless even when damaged by impact energy.
However, if some amount of liquid fuel enters the canister 112 from the fuel tank 111 by a certain cause, it is preferable that there be no leakage of liquid fuel from the canister 112 at a rear-end collision. It is thus desired to improve canister protecting performance to avoid leakage of liquid fuel from canisters.